Tube recomendations for a newbie

I believe tube rolling can make a big difference in the sound of the component. Whether or not rolling the originals out of the Migda will be better or not, only you can decide.
I've had great luck with sellers here on A-Gon, as well as Jim McShane (google, you'll find him). Jim will help you get the right tubes for your amp and your preferences.
Personally, I would recommend you begin with the 12AU and 12AX tubes. Cheaper, and my experience has been that they affect the sound more (certainly as much) as the output tubes.
Have fun!

http://www.audioasylum.com/scripts/d.pl?audio/faq/joes-tubes.html This site has a lot of information and Joe reviews a lot of different NOS tubes. As Elizabeth said it can be fun and really frustrating chasing the best tubes. You may want to get used to the amp first and do some reading. It might also be good for the amp to burn in and make sure everything is settled. Maybe a few hundred hours? Then take a chance and see what you get

Thanks for all your good information. I will take a wait and listen longer approach before I start to mix and match.

"One thing I am certain of, Chinese tubes are getting better, and they will be up there with the good tube makers, and perhaps wind up being the best of all!"

I couldn't disagree more, Chinese tubes suck!
I have two Chinese amps.The Bada DC-222 integrated amp that came with stock 12AU7 Chinese tubes and a Shengya A10CS Hybrid Integrated Amplifier that also came with stock 12AX7 Chinese tubes
Both amps didn't sound good at all at first, then I replaced the tubes with some cheaper NOS ones and now the amps sound great!!
The Chinese are starting to make some really good sounding gear but they have a very long way to go in regards to tubes! I personally haven't heard any good Chinese made tubes as of yet, in fact I throw them away.
You don't have to spend a fortune to get some really good sounding tube replacements. You can buy some nice NOS 12AU7 GE's,RCA's, J&J's among others at very decent prices and as far as the 12AX7 tubes there are current production tubes that are really good like the re issued Tung Sols and Mullard's.

This came from the Pacific Value site that sells your amp.
We recommend that you leave the JJ blue tubes in there as these should
be the last to go.
Get rid of the stock 12AX7 / 12AU7.
Try the Mullard 12AX7s - these worked the best. For 12AU7s - try the GE 5963s or the Sylavania 6189s both of these tubes worked well.
Need more bass? Try the EH 6CA7s - very good tube for the money.

Tube rolling can be fun, and it can certainly make a meaningful difference. I do it all the time.

But it is a learning process and you must start with an objective, that is, after your unit is well broken in you have to be able to identify what about the present units sound you want to improve and identify which tubes is most likely to get you there.

Then you have to identify the tubes which can move your sound in that direction. BTW, I usually expect to get larger changes using power tubes and smaller, but more critical in the final analysis, from small tubes.

You are right to take your time! But start reading up on the subject by following the forums and seeing what users have to say about the general quality and tone of the available tubes used in your amp so when you do decide to move you will be reasonably well informed and have a good basis on which to begin.