Your Risk of Ruin has little to do with the count you employ.
You mention a 10% Risk level.
If you were what we call a "Full Kelly" bettor, you would [try to] bet in accordance with your advantage.
With a $1,000 bankroll you would be playing with a Maximum bet set at +5 Hi-Lo True Count - where you will have nearly a 2% advantage.
Many days you will not reach such an elevated advantage, but when you do you'd be wagering your MAX bet, which would equate to 2% of your bankroll.
[That would be $20, presuming that you still had $1,000]
With $1,000, presuming that you could find a $5 game with its attendant poor rules,
you would be facing a disadvantage of approx .7% in most cases.
This would almost always be a 6 or 8 deck shoe game.
To beat that game you would need to spread perhaps 12-1 or more. Optimal would be a MUCH more aggressive bet spread.
So ... your Maximum bet would be (at least) $60
Of course, with splits and double downs you would (sometimes) be betting 2 or 3 or 4 (or more) times that much on a single hand.
Ordinarily I recommend having a bankroll between 800 units for a good Two Deck Game up to 1,400 units for a 6 or 8 deck shoe game where the dealer hits soft 17. Another popular way to look at Bankroll requirements is to look at your Maximum Bets. I usually suggest from 80 to 150 Max Bets.
So if you played a $5 game with a $1,000 bankroll, spreading to $60 you would have 200 units [and 17 Max bets] may earn about $10 - $15 per hour but your Risk of Ruin would be perhaps > 40% That means that you are almost as likely to go broke as you are to double your modest bankroll.
That many units could very easily be lost in the course of a single session.
In most venues the minimum game that can be had is $5 but in many places it is 2 or 3 times that.
You have to determine what games are (geographically) available to you. The stakes and the rules. The number of decks and the (apparent) penetration.
You are correct that a strong count will help you but it is actually a secondary consideration.
The simple "Level One" counts that are popular, e.g. Hi-Lo, K.O., etc are good enough for a shoe game BUT are NOT good enough for as "pitch" (hand-held) game.
More on that after you follow up your initial post.
