Stay away from chains of digital effects. I'll kill your tone and linking a lot of stuff together can easily turn the signal to mud and create noise. It's also a bad idea putting distortion at both ends of the chain, especially digital. For the price of all that you can get a decent valve amp that can roar like it has a solid pair.

Also, if you want a clean solo sound, you're not going to be distorting it. A little overdrive might be good, but you'll want it as pure and analog as possible to preserve richness.

For clean solos I like guitar-->maybe a little reverb and/or delay-->speakers. Nothing more, besides setting the eq.

By synthesizer do you mean like something for guitar or something like what Pogo plays?