You are correct, you a pack 140X50 and under to fit the Ve8. I recently got one myself and just finished putting it together today, no picks yet though.

here is a list of other packs that fit along with some hobby city lipos (and others of course), got this off of RCTech.

HYPERION
G3 CX 4000 MAH 4S 14.8V 25C/45C

G3 CX 5000 MAH 4S 14.8V 25C/45C

G3 VX 4200 MAH 4S 14.8V 35C/65C

THUNDER POWER
Hardcase Li-Polymer Battery 40C (14.8V/4200mAh)

Hardcase Li-Polymer Battery 40C (14.8V/5000mAh)

SMC
5400mAh/40C+/4S/14.8V Soft Case

5200mAh/50C/4S/14.8V Hard Case

PRO-MATCHED
5100mAh/40C/4S/14.8V Hard Case

REEDY
5000mAh/40C/4S/14.8V Hard Case

Hope it helps, I can't wait to get mine on the track, I'll post up some picks when my bro brings my new lid on the weekend.