to my knowledge neither are pressurised.
Up to 18000 ft you can use canulla's for oxygen, a good system being Mountain High O2 which feeds oxygen ondemand (pulse). It is a fully automatic setting which requires only a small bottle. The downsize is it runs on 2 AA batteries, so you must make sure you alwys have spare ones.
Above 18.000 you ll formally need oxygen masks which are less comfortable.
Many unpressurised planes fly in the 12.000 to 25.000 band, because the air is generally more smooth, it is more fuel efficient, faster and generally above the weather.
To practically fly there however, life is a lot easier with an IR rating