Look around on Astromart in the USA... You could get a TMB 80mm F/6 like mine for about $1200~1500USD, and use a Baader MPCC to flatten the field, or the Televue TRF-2008 to flatten it, and reduce it to F/4.8 @ 348mm focal length.. I think 348mm is a bit short for most targets, so I use an MPCC to flatten the field and it works brilliantly... I get no vignetting over a DSLR sized sensor which is always a plus...
Its no Tak FSQ106, but its way cheaper!
The next best, slightly more expensive option would be at about $2800 USD for the Tak FSQ85... Now that - That will do exactly what you want, with no need for a flattener... Expensive for an 85mm APO, but you won't find anything that comes close in the same price bracket I dont think.. Especially when you factor in that nearly everything else will require a flattener...
The TV 102iis is another option, but its at about $4000 from memory, and at that price, Monte Wilson's FSQ106 for $3800 in the for sale forum looks like a mighty good deal!
The FSQ106 is -THE- wide field imaging scope in my opinion. the FSQ85 is the next best thing... Anything else is a sacrifice due to funding constraints, however there are options out there that deliver outstanding results and much less cost.. Just dont expect a dead flat field without chromatic aberration without laying out big dollars to get it..