Oil drain to do a Head/ Head Gasket RR? + more

[Kid Rock]

Well I think I may be up against a gasket/head issue like @Waterloo and others have experienced recently. The truck now has approx 860,000 mi with very low idle time (only for warm ups and cool downs). I will know more I suppose after I test with the exhaust gas leak test that Napa sells. I'm not losing coolant, but little bubbles have been appearing more lately. I've been dealing with this for about a year now, but it would go away so I don't know. I take very good care of this truck, it is driven by me @ 10 BST or bellow 98% or so of the time & the oil is still golden at 15k. I need to do an oil change but I think it may be head time too... I don't want to waste ANY money if I'm actually at this point right now... So my questions to the community is:

1) does the oil need to be drained to do the head/gasket RR?
2) are the head gasket kits off eBay worth looking into? ($450 range)
3) (not a question) I already know from research here that the new Head is the way to go
4) how much should I expect to spend on the new Head itself/Gaskets/ + Labor. I plan to schedule time with Mr. Hag because i could hardly justify spending this type of money with someone on the outside who has no reputation for quality and pride in their work.

Maybe this thread could help a few others along the way and as always, thanks in advance and Safe Trails to you all :)