Nikon to telescope adapter

Seems that I am becoming more confused the more I read here.. Have purchased a second hand beginners telescope, 60mm - 900mm. Did not have the money at the time to go and buy what I think is called a prime focus adapter. So I made my own. I connected a old Nikon M2 tube to the end of the focusing rail, this allows me to connect a Nikon D3000 body using one 2x teleconverter to the telescope, I can focus in and out using the focusing rail wheels. This works , but there are so many quality control issues I need to get the proper adapter. All I am looking for to buy is a adapter that will mate to both F Mount Nikon to the telescopes diameter on the focusing rail. - In searching the internet I find T-adapters, and all number of things they wish to sell me.. - what should I be getting? 2nd Question , if in the future I want to install say a 40x eyepiece to take photos of the planets what would I need to get? - with everything when starting out it is difficult to understand.. I think I have a fair knowledge of what I need but , just gets a bit confusing with everything on the internet.. - I'm in Minnesota, they don't seem to have many telescope shops anymore.. So I will most likely be buying something off of the internet this coming month. Really wanted to actually talk to someone knowledgeable about such things in person.. Thank you..

Yeah, fixing it in position is always a bit of a problem...

But first, you don't need to have a eyepiece; the camera is the eyepiece (the telescope becomes a camera lens). And no need for a 2x teleconverter either...
Its a lot simpler to just have an empty hole to fit your Nikon adapter into (Prime focus photography).
The T-mount adapter connects your SLR to a camera adapter (ie T-Adapter and T-Ring) which is the correct size for your telescope, (eyepiece size .96, 1.25 or 2" - yours is probably 1.25")

(you just need two components - T-Adapter and T-Ring)