hey OP the guy who says you cant use mssiah without modding shit is off his face.
You dont need to solder shit if youve got some midi hardware with knobs that send cc's (like a midi keyboard with faders on or whatever) And the sound is of course a c64. 4mat and all are very right when they say a lot of the character comes from the idisynchrosies of the programming the sid via tracker/ editor interface, but that guys like a veteran of the scene! Most (vaguely chip oriented) people will just hear that classic PWM occasionally clunking timings and go, mmmm C64!!!
on the cheap/ easy route you have mssiah/ goat tracker/ (++sid duzz it?? not sure)
on the cheap and hard (and maybe not worth it) you have cybertracker.
and all the rest fall into paying a load for some discontinued or small run synthesizer hardware using the sids as hearts; sidstation (too expensive, limited compared to sammich) hardsid (just sits at your PC in a rack with like no controls) sammichSID (discontinued) and MFB xxxx (midibox SID x 8; daunting if noob with building electronics, sourcing the parts seems the scary bit)
so really it is not an easy solution for you; either man up and learn SID music programming and a tracker, and pony up and prize someones sammich/ sidstation out of their hands or buy a load of stuff to build the expanded midibox sid.
i say, download goattracker, and try buy mssiah. use both until youre sure u will or wont get into trying to learn Goat. then save up and get hold of a midibox sid of some kind