[GpsFrontier]

Hello Rye,
First, I could be wrong but I think your statement "I am using 400w t5 jump starter light" is wrong. Each 4 foot T5 bulb is 53 watts. 400 watts would mean your fixture has 8 bulbs. If you actually do have 8 bulbs and 400 watts of T5 florescent lighting, that's plenty to grow lettuce.

if I am growing Romaine, spinach, and kale, will a 1000w burn them?

It depends on how close the light fixture is to the plant. Any bulb can burn the plants if the bulb is to close. If you can hold your hand near the foliage, and it doesn't feel to hot it should be fine. If it is hot, the bulbs are to close.

given as MH, and hps each favor one end of the spectrum, which end does lettuce prefer? Red or blue?

Blue....
MH (metal halide) mimics the high summer sun and promotes more of the vegetative growth. Since the goal of growing lettuce is vegetative growth, and not the flowering/fruiting cycle, the better choice for growing lettuce would be MH (the blue end of the spectrum).

HPS (high pressure sodium) mimics the late summer sun. When the sun is lower in the sky. Because of the suns lower angle the sun's rays have to pass through more of the earths atmosphere. The atmosphere causes the change in spectrum. Plants have evolved over billions of years and know when the days get shorter and the light spectrum shifts towards the red side, summer is about over and it's time to fruit/flower before winter sets in.

I am looking to upgrade to a better light system, and found one for sale used locally. It's an apollo 1000w system.

How much are you planing on growing? A 1,000 watt light is going to be expensive to run. Have you given any thought to whether you will be making your money back or costing you more to grow than buy. What's the point of growing your own head of lettuce if it costs you $6 to grow, and only costs you $1 to buy it at the store.

I pay 9.3 cents per kilowatt hour. National average is 10 cents. A quick rundown using what I pay, this is what it will cost:

1,000 watts for 18 hours a day= $1.67 per day to run.
$1.67 x 30 days= $50.10 per month

The ballasts uses electricity as well, typically between 8 and 15% of the bulbs wattage. Using 10% of the bulbs wattage for the ballets= 100 more watts
100 watts for 18 hours a day= $0.17 per day, x30= $5.10 per month.

Just the lights alone will cost around $55.20 to run (using 9.3 cents per kilowatt hour), and that is just for the lights. That doesn't include fans for air circulation, nutrients and pH adjusters, pumps etc... If your not going to be growing and consuming $100 worth of produce each month you'll be loosing money.