I use 11 to 48 (or 49), the G is usually an 0.18 plain which is quite bendable once you have worked a bit.
Best I've ever used are DR Handmade Blues.
Tapewound/flatwound strings are also a good option, usually have a wound G but long-lasting and have a great feel and tone when you get into it.
For these Thomastik-Infeld are amazing but D'Addario are cheaper and well worth trying.
Keeping intonation; note the position of each end of the bridge in relation to the f-hole, it should be near the wide point. Many (but not all) f-hole guitars are designed so the bridge lines up with the wide bit of the f-hole. Use that and the bridge posts as your guide. If you remove all the strings to clean, when putting new ones on, do the low and high E strings first which will hold the bridge on. In the past I've also glued a thin strip of felt to the underside of the bridge to cushion it when you adjust it with the strings on. Basically all you can do is intonate the 2 E strings and hope the rest will line-up ok. When you get it right, it is worth making a mental note of the (approx) string length measurement from tailpiece to bridge too.
Another tip is to measure the distance from nut to 12th fret; it should be the same distance from the 12th fret to where you place the guitar bridge.