The place for musicians to share their knowledge and ideas about music and remixing, and to post WIP snippets and feedback. Also suggest tunes for remixing, here.
Well... I know a bit about old-school techno, so I can give you a few idears:
Roland MKS-50 ... analog rack version of the very popular Alpha Juno... This machine is famous for it's then much used "Hoover" sound... the MKS-50 was a general well used machine for much techno back then in the early 90's
Waldorf Microwave (version 1). This digital/analog hybrid has digital oscillators, but analog filters... 8 voices... it sounds fabulous and is capable of sounding both digital and analog... can do some pretty harsh techno leads
Yamaha TX81Z ... digital FM synth, good for warm punchy basses, especially in GOA music. An alternative is the Yamaha FB-01, which is also FM, but can be found usualy dead cheap. Yamaha DX-7 as well.
If you need that "orchestral hit" sampled sound that many a techno-track used in the old days, I'd go for a simple sampler or ROM'pler from E-mu Systems... The E-mu Morpheus that I've got is rather good at this, and has excelent digital filters also... maybe some of their earliest tone-modules like "E-mu Orbit" would also do you good, and they come pretty cheap these days.
Maybe you can even find a cheap Yamaha An1X keyboard... has been used on many techno-tracks as well.
In general I think you can't go without some sort of sampler for some sounds, and percussion... samplers was used widely back then also.
Otherwise, anything analog or digital out there could be used with good effort... like:
Clavia Nord Modular
Roland JP8000
Korg Proteus
Korg Wavestation
Roland D50/D550
Waldorf Microwave 2 (digital version)
Korg DW8000/EX8000
There are plenty of cheap solutions out there, but ALWAYS check it's MIDI specifications to make sure it will need your expectations!... much gear from pre-90's have limits or are quirky... so be careful.
emu-orbit v2 - once i had the v1 and was not impressed, but v2 rocks)
korg poly 800 - nice sounding synth, loved him)
casio stuff in general, always played trough some guitar-fx.... i had some of the old 80s synths....
kawai k1m - nice soundmodul, very good for moving padsounds...
quasimidi technox, and raven... and some other quasimidi stuff from the mid 90s....
yamaha cs1x, cs2x and anx1...