Couple of things...
You say you have a studio rig. What's in it as far as instruments (ie: synths, drum machines, sequencers, etc) already? This is going to be a major key to what should go into a modular rig and will help determine what sort of focus the build needs to have.
Second: I hope you're not expecting that the equipment is the thing that will make the music work. Truth is, that's on you...not what gear is at your disposal. A modular of any workable size is a hefty expenditure, both in money to outlay for it and time spent in getting how you use it sorted out. You can have a Synthi 100 at your disposal because you had the $50-100k to drop on it...but if the talent needed to make that spendy thing really sing is lacking, that's not a wise purchase.
Last: there are a LOT of machines to 'make techno music with'. Fact is, the people who started all of this (the house guys in Chi, the Belleville 3) were working with crap they could afford from want-ads, used music shops, and pawn shops. That's what shaped how techno sounds to this day. If you don't have experience with electronic music gear on the basic levels, such as with older gear, patchables, etc and thinking starting with a modular is the 'big secret'...guess again. It would be like trying to go through driver's ed in a $500k Ferrari.
Just sayin'...