Two Plus Two Older Archives - Fantasy Football question

12-team h2h $3,500 winner-take-all league, start 1 QB, 2 RB, 2 WR, 1 TE, 1 K, 1 DST
3 divisions, four playoff spots (3 division winners, 1 wildcard)
My team (6-4, 1 game division lead):

QB: Mark Brunell, Ben Roethlisberger, Chris Simms
RB: Tiki Barber, Antowain Smith, Duce Staley, Brian Westbrook, Cadillac Williams
WR: Donald Driver, Hines Ward, Jimmy Smith
TE: Chris Cooley
K: Lawrence Tynes
DST: Bears

Do I need to make a trade and what area do I need to improve? NOTE: My league has a strict trade approval process. I'm not looking to make a blockbuster here, rather improve my depth for playoff time (I'm only 1 game ahead in my division, but the other teams in my division aren't that strong either). Who should I target to improve my depth best utilizing the depth I have already?

There's one team that I've been going back and forth with all year with offers, but never got a deal we could both agree on. He happens to have the best record in the league (8-2). Here's his roster:

QB: Marc Bulger, Jeff Garcia
RB: J.J. Arrington, Ronnie Brown, Mewelde Moore, LaDainian Tomlinson
WR: Larry Fitzgerald, Torry Holt, Darrell Jackson, Chad Johnson
TE: Jerramy Stevens
K: Neil Rackers
DST: Bucs, Lions

What would be a good offer that will best improve my team that he'd accept (he's pretty stingy, but so am I)? Any and all insight is greatly appreciated.