Originally Posted by SirDracula
Budget ... as little as possible that still performs better than what I have, throw some ideas out there.
What do you define 'as little as possible' as? $100? $200? $300?
If you want to try a bookshelf as a center, just go up to BB, buy a set of Sony Cores at $120, use one as a center. Keep the spare as a backup, or use as rear surround, or sell it. Normally I wouldn't recommend it unless using Cores all-around anyway, but no idea what matches your current in-walls, and it doesn't seem like that matters to you anyway, if using a PC1000 currently.
Other options... PC2000, as has been mentioned. It's basically just a larger, more full, version of the PC1000. But it's not worth $300+ in my opinion. Even at $200 for refurb prices I really wouldn't recommend it, unless you had def tech all around already or simply love that sound signature.
Bookshelf as center options: SM45/55/65 from BB, but only if you prefer the def tech sound.
JBL 230 I would have recommended, w/ free returns, but see it's no longer for sale at $250. JBL Arena C25 would be $100 from amazon, but no idea how it sounds.
RSL CG23 would be $200 w/ free returns.
RBH R56Ci is $200 on clearance, but only in red burl.