Paint contractor questions

[Josh C.]

I have a rental I am currently rehabbing and have a paint contractor about to start. This house hasn't been painted in 30 plus years and his plan was to power wash and scrap what's flaking off, but leave some "alligatoring" which is typical for the area (not really my issue). My concern in the paint and it primer. He was planning in using Benjamin Moore ultra spec exterior paint two coats but no primer. Wouldn't you want a primer on a combination of old paint and bare wood? I don't think the ultra spec is even a paint and primer in one, the only reason I'm using it is he has a hook up and it's cheaper. Second question what's the best exterior paint for wood siding and this application? I plan on having this place a really long time. For all the wood repair and prep work I am already at 12k for the whole paint job so don't want to add, but will if it will be best for the house. Thanks a lot!