well there's absolutely nothing in there that I'd put in - including the case
start with a bigger case - you'll probably want to expand from this once you've got it and having the space already available will save you buying another case... bigger cases are often better value per hp and have better power solutions - tiptop mantis is near perfect starter case - buy (or make from cardboard) blank panels to cover the unused space
as a multi-effect unit I'd want one with a screen so it's easy to work out what algo you have loaded - fx aid pro would be my choice... because if you decide that you want another multi-effect you can then buy another one - either the standard of the xl and if you set it up right you can use the pro as a reference for the algos on the others - 1st 32 algos on the pro match the 32 algos on the other modules...
I wouldn't buy b-company modules without comparing modules from other companies - ie don't just buy something because it's cheap... find the one that you actually want - spend a lot more time researching before you buy...
you'll probably want to amplify the sub37 so it's actually at modular levels for processing
you will want more modulation and utilities than you think - these will exponentially increase the flexibility of the rack - they take up space - back to get a bigger case!!!
something to consider is that in order for a modular designed as an effects processor to be worthwhile - it is a full blown modular synthesizer, with an external sound source replacing the vcos - everything else is identical...
"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia
Utility modules are the dull polish that makes the shiny modules actually shine!!!
sound sources < sound modifiers < modulation sources < utilities