If working within this hp space I would recommend two Arcus Audio Dual LIN/EXP VCAs. I would also suggest looking at the X-PAN from Make Noise as your mixer, especially for ambient. Do you need to run 1/4" cables from the rig or need headphones from it? Most audio interfaces can handle this duty. Roland makes some good 1/8" to 1/4" TS cables. I would suggest the Klavis Mixwitch as a sequential switch. The Happy Nerding FX AID is a great effect module. As far as oscillators I recommend allowing whatever hp you need to get what will work best. The BIA is a very popular module. Filters are also a very personal choice. I like the VOID Modular Sirius' Veil. I would also recommend a LPG. ST Modular makes a 0 hp Workmate if you want a flying LPG. Mystic Circuits also makes one. This also is lacking in utility modules. I suggest drawing out the signal path to see if there are any choke points or gaps.