You need to decide on your Bankroll amount
If your BR is $15K, then you have a ton of additional options.
Bankroll is defined as the amount of money that you are willing to lose. If you have a $15K bankroll, then you are willing to lose $15K. If you don't want to lose more than $1K in a 6 hour trip, then you have a much smaller effective bankroll.
First off, you need to decide what amount you are actually willing to lose at this game. That amount is your bankroll. Abandon the concept of session loss limits (or win limits for that matter). The only thing they limit is your potential to make money.
Second, you need to decide on your risk tolerance (just like when you are deciding on investments for your 401(K), etc. Ask yourself whether you are willing to have a 5% chance that you will go broke if you do everything perfectly. If your honest answer is "yes", then use a 1% ROR for calculating your bet sizing and ramps (because you won't do everything perfectly).
If you decide that you are in fact willing to lose $15K (and you have $15K available), then do the following before you play another hand of blackjack:
1. Buy and read Blackjack Attack, 3rd edition.
2. Join Green Chip and read every post in the archives.
3. Buy the Qfit software, or at least BJRM
4. Subscribe to CBJN.
Once you have done those things, you are ready to start playing. If you are 3 hours from Tunica, you may have much better options available, but it really depends on which direction you are talking about. Are you North, South, East, or West of Tunica? Don't answer that. Just get CBJN and see for yourself.
Regardless, playing a 1-4 spread at a mediocre DD game is not your best plan, if you want to maximize your earnings. If you are just wanting to get some experience, that is fine, but I would recommend a $5 - $20 spread instead if that is the case.
With a true $15K bankroll, you can afford to take some inexpensive trips to places with really good games. You should do so.