I would either do a Whittaker type machine, or a cimex. Both can clean multiple surfaced and be operated by one person (cimex has the advantage there) but you really can't go wrong with either of those. Taski also makes a great LM machine and you can control the humidity of it so dry times are faster..... But since it's low Moisture it dries fast. Also can be great machines to add to HWE. An easy spotter (or hand extractor) is a great little time saver as well.
PS Virtually every SFS graduate I know swears that the Cimex is a cash flow machine... IF you get the work to keep it humming along. (I know people that have paid for the machine in one long weekend!) Of course, if the Cimex isn't kept busy it is just an expensive obstacle gathering dust in your garage!