Funhouse and taxi have lots of parts available

Funhouse

Harlem Globetrotters
For a first restore, keep it simple, more likely to finish
All the parts are available

It really depends on what each game needs.

Any one of those titles could a good candidate. Although, nice playfields might be tough to find for F14, Genie, and BH (although Mirco has BH in the pipeline for reproduction).

For starting out, I'd say an early solid state would be best to work on. They're relatively simple games, and easy to disassemble/reassemble. However, you do have to be careful about sinking more money into them then what they are worth.

If not a purist, you could look into the Hardtop option. Would run you about $300 for "playfield ", plus time and destroying the old graphics.

If you need ramps, etc, that would be extra.