IMO, you're overpaying for the Xense. I find the PC350 combo to be stupid. If they ever get rid of the headphone combination with the Xense and just lower the price that'll be a sweet card to get for people wanting 5.1
2nd, the AD700s are a good choice for you. Trance, Progressive, Alternative aren't bassy types of music (At least the kind I listen to) and the AD700s sound better to me than the HD555s even modded. Basically, music sounds more lively and entertaining than on the HD555s.
However, the best your money will buy you in this range are the DT880s probably. 990s if you listen to trance that is more bassy (All trance I've listened to is high treble though tbh) and Alternative and Progressive from my music collection is typically not bassy so the 880s would be better.
HOWEVER, the DT880s crave an amp so..unless you're willing to invest in an amp for additional dollars, the DT880s are now out of your selection.
Can jump for the AD900 or A900s if you feel inclined to spend more, but I couldn't really justify spending the extra 110 dollars for them.
How much bass do you listen to? If you could dish out for an amp, the DT880s would have been a really nice choice, but I don't want to force you to spend a lot of money. It's just when you get into audio, your wallet goes out the window most of the time.