So since I might need a side character to help with certain matchups, who do you guys think might compliment Sim?
It just depends on what you want. If you want a character thats def different, but still controls space and such, Ryu, Nash, Guile, etc all fit the bill.
If I were you, Id work on a Ryu. I say that for a few reasons.
Ryu is strong. He goes even or better with mostly the entire cast and the closest he gets to losing a MU is something like a 5.5 against him, and even that is mostly debatable. Despite what some people think, he has a number of winning MUs as well. Nothing drastic, 5.5's in his favor. As Ryu you never have to be terribly worried about who the other guy or gal is going to pick.
Ryu is also unlikely to be adjusted much/at all come S2. Some characters I feel are going to play differently come S2 and investing time in one that might be changed significantly isn't the best decision. Even if Ryu was 'adjusted' it wouldn't be drastic.. Ryu has always done and had certain things.. they arent going to take those away. ie, its very likely his gameplan and what it takes to win as Ryu will be the same then as it is now.
Ryu is built on fundamental play. Skills learned playing Ryu will transfer to any character in the game. Of course thats true of.. well, any character in the game, but Ryu I feel embodies this much more than others. He's a great secondary character, AAing, understanding your frames, command movement (this is very important in SFV I feel), proper spacing, fireball game (Playing as Ryu will help you on characters who dont have a fireball because you will understand the holes and weaknesses in a fireball game and you'll be better able to exploit them). The right normal for the job at hand. The list goes on.
Ryu has all the tools. He really does. He has something for every situation and if SFV offers it, Ryu not only has it, but his is, if not the best in the game (or tied for it) its right up at the top. You can define 'tools' in numerous ways, but as quick run down he has:
• Damage: Some of the best in the game. (I consider this a tool. The threat and knowledge of this effects the match just like a normal or a special move. You know vs Ibuki you can take a couple risks. You vs a Ryu you cant)
• 3f Normal and Invincible Reversal. His st.jab has shit range but will AA you in Ohio when he's cooling out in China. Shits ridiculous. It will perform all the usual defensive purposes and pressure interruption a 3fer should and it will AA a CC after its well past the back of your head. His reversal is one of the best in the game. Great damage. All the benefits of an invincible reversal and since it doesnt need meter to be invincible like several DPs in the game, and its 'arc' of motion is pretty direct its hard to beat. Guile's can be jumped past with good timing and positioning, Juris can as well, so can Ibukis.. Ryu's much less so. Not to mention it will auto-correct itself a lot of the time without you doing anything. I DP people who get over my head all the time while doing nothing different. These two tools DRASTICALLY change the wake-up and pressure game in V. Drastically.
• Good Health, Stun and dashes with reasonable walk speed.
• Air Superiority. He has amazing AAs. Cr.fp, st.jab, DP, etc. He has amazing A2A's.. j.mp (this can cancel into ex air tatsu on hit.. No one does it, but it looks cool and surprises the shit out of people.). You can, with good timing, land a CA off j.mp I BELIEVE. Dont take that as gospel just yet, but Im pretty sure you can. Air tatsu itself is great. His isnt on Ken's level, but it still alters his jump arc and gives him amazing priority in the air. He has amazing jumping buttons and a reasonably good jump arc. Its direct and the point.. not floaty or slow at all. j.lk is a crossup that alters his jumping hurt box, so its deceptively difficult to AA and will beat a LOT of AAs clean. You can confirm in to ok damage and it crosses up at pretty close range, giving him a ton of spacing options. J.mk. Nothing special about it as far as its hurtbox, it can be AA'd normally, but it does ok damage, cancels in to great damage on hit, has good range and will crossup as well, making your jump-ins more dangerous and ambiguous. j.hk/hp are normal jump ins. Absurd damage, good range on the kick and the punch is harder to AA than it would seem.. it doesnt beat AA's clean really, but will trade sometimes. Nothing special but its nice to know and keep in your back pocket.
• Great normals
Im getting sleepy. You get the idea.