Mine do well on packed spaghnum cage/bag mounts, and I’ve heard they do well in self watering setups too. I think the most important factor is environment. If your greenhouse is very humid but cold keeping the spagh too wet can be an issue too. So good airflow and the right temps will be just as important as the humidity if you want to get the watering right. But I think humidity can be a bit lower if you keep the roots moist as compensation. For most houseplants thickness of leaf means losing less water to the environment and bulbo leafes can be pretty sturdy
For species I think everyone should have a mastersianum. They don’t ramble, grow quick, are fairly small, and the flowers are (in my opinion) amazing! Lepidum is great in the same way, freeflowering with increased frequency in the warmer months.
If you are nervous about it you can always go for some hybrids between some easier species to start with. Hybrids are usually more forgiving and tolerant to a wider area of conditions. Elizabeth Ann Bucklebery for example, and very attractive flowers..
I don’t have much experience with bulbo’s yet, took the plunge a few months ago and it wasn’t as much of a hassle as I feared. The way my nearby nursery sells them mounted has helped enormously with that. For sure try it out, bulbo’s are very worth it!
Hopefully some other members will be able to give you some reccomendations on what some forgiving beginner species/hybrids are