electronic ballasts are terrible generators of interference. This is a bit pricey, but it should help with the problem.
https://www.amazon.com/dp/B000OF4R8C/?tag=atomicindus08-20
http://www.awc.org/codes-standards/calculators-software/spancalc
Is a good source. Live load and dead load are key. At 12" on center, 19'1" is acceptable for a 2x10. Sagging says that dead load probably exceeds 15psf.
The biggest problem I have seen is underestimating the future. If you are considering a new panel in the shop, don't short yourself on breaker space. You didn't say what brand panel you have in the house, but you can buy a 200A feed thru breaker and safely and legally feed a second 200A panel...