Unless you know a dealer who has unify in stock, its gonna be difficult to find.
On this stage of your system, Maths and quadra are overlapping a bit, though later on you will have use for both.
I think that DPO pairs really nicely with echophon, so I would go on with that, instead of EV. Both are very pricey units, and there is good options also on the cheaper end of verbs and delays.
Dont know how you´re going to clock it, you might be needing some distribution/generator for that, random source with a clock, like wogglebug etc. is handy.
Z2040 sounds really good and Rene is fun to play with, overall its a nice to system to start with.