My Story -- Bankroll help!

So about a month ago I turned 18 and opened a checking account at the local bank and soon afterward deposited $100 into a partypoker account and started playing the NL25s and a few SNGS (5s and 10s). I had just read SuperSystems and took every word written in that book as truth.
By the end of the day, my 100 was gone. I took the book too seriously, especially the part about making a loose/gambler table image and to play the next hand after winning one because *STREAKS HAPPEN*
So I almost immediately deposited another 100 and played more conservitavely and started building it back up, slowly.

Over the next week, I picked up a few book (HOH, Theory of Poker, Advanced Tournament) and began studying the game from the point of view of much more conservative players. I began playing this way and making more and more money. Once I got up to about 250-300, I moved to NL50s and started dominating. I tried doing 2 tables at a time and it was working fine. Then 3. Then 4.
Once I hit about 500 I moved to the NL100s. I was playing the same game, no matter what the stakes were, and it was working quite well. The problem was that I was moving up the stakes WAY too quickly without a big enough bankroll. Before I even had a grand in my account I would play with 2 tables of 400 EXTREMELY tight. It was rediculous. I ended up getting my rankroll to its peak at 1.2 grand (therefore 1,000 profit) within less than 3 weeks.
And I kept doing this. Multitabling with my whole bankroll on the table! I ended up catching a bad streak of cards and losing some giant hands. After losing my first 400$ hand, I finally realized I was doing somehting wrong. I stepped it down to NL100 (which was still very high for my bankroll, which was now about 600). I even tried the 6 person tables and played MUCH more agressively, bluffing way too much.

Needless to say, I lost it all. I was down to 30$ one night when I decided to invest it into 3 10+1 tournaments (which I, of course, played at the same time). I told myself that if I lost this, I would take a LONG break from poker and get my mind right. I forget how I placed in those tournaments, however I know that I won them. I stuck with the 10+1s and within about a day turned my bankroll back to the 200 I started with.
I played the 10+1s for about a week straight and had a good win streak going.

So, to make a long story short, I have been consistently winning since then (about 2 or 3 weeks) and have built my bankroll back up to about 800. I cashed out most of it and have about 200-250 in the account now.

My question to ya'll is what stakes should I be playing? I'm multi tabling the 25s now and killin the donks just playing real solid poker. TAG.

How many buy-ins would you guys recommend to have before moving up in the stakes again?

Thanks in advance.