Legally the panel has to match the meter base rating or less.
If you're building this service with new components, The meter base may be rated 100 amps. If so, a 100 amp, or less, panel will work. You can't put a 200 amp panel on a 100 amp meter base.
2 240 volt outlets on a single tandem breaker will work fine with one machine on at a time.
208 volts? 208 is a three phase spec. 208 and 240 are not the same. I have seen many 240 A/C units die early on 208. A truck stop near here bought some 240 volt units and connected them to 208. They lasted one season. The next summer, they started failing. The heat alone must have been excessive from running underpowered. Running the machines above the rated voltage will surely affect the performance an lifespan.
My wood shop probably never sees more than 35 amps at a time with maybe a short 50 amp surge when the compressor starts. It's on a 100 amp panel and works fine. The most load is; the lights on, a table saw running and the compressor kicking on. That's the only time the lights dim at all.
8' flourescents use about the same as a 100 watt light bulb. You won't have a problem running 4 at all.