What do you think should be my next audio upgrade?

[BLindsay]

Hey all, the upgrade bug is making its rounds again and i was wondering what i should upgrade next audio wise. what do you think is the weak point in my system at this point?

Here is my current setup

Power: Emotiva UMC-200, XPA-3, 2x UPA-1
Fronts: Polk LSi15s (Upgraded crossovers and woofers)
Rears: Polk LSi7s
Center: Polk LSiC (Upgraded crossover)
Sub: Velodyne F1500 R
Blu-ray: Sony BDP S580


I listen to about 60% Home theater and 30% 2 channel music and 10% multi-channel music.

My thoughts were either to replace the 2x UPA-1s running the fronts to the Emotiva XPA-1L's ($1400 for the pair) or a subwoofer upgrade, which i cant even decide on that but here are a few thoughts for that.

Martin Logan Dynamo 1000 ($1000)
2x Martin Logan Dynamo 500s ($1000)
2x SVS SB-1000 ($1000)
2x SVS SB12-NSD ($1200)
JL E-110 ($1500)
SB13-ULTRA ($1600)

Ideally i would want to stay around $1000 (the amps i could sell my current ones to bring the net cost to around 1000) but i could go a little higher if the subs really were worth it

or perhaps you thinking something else is the week link?