Xbox360 - Shooter Firepower

Here i am, just finished up writing some nice succinct code to setup the firepower fro the player ships with a  nice table per level. It is cool. But now i have the firepower upgrades all done, and each level you basically get an upgrade or two to your firepower, i realise i am not sure i wanna do this.

So the idea i had for the game, was every level your firepower gets upgraded. This would be exciting, and i can make the aliens behaviour slightly different for each level and the type of firepower you have. I realise now a few issues though, now i have it working, bah!
Issues:-
1. Hard to balance levels with ever changing firepower. Not impossible, but tbh it would take a lot lot with constantly changing firepower. Not sure i wanna spend that kind of time, when i do not think the general player will really notice the subtelty.
2. Not sure the general player will notice some of the firepower upgrades. Oooh, speed of my primary forward fire has gone up a notch.. Hmm. Maybe not enough of an upgrade to be really noticed.
3. Creating more alines than i would usually have to to combat the firepowers is a big job. If i have say 10 different firepower setups, then i only need to really design 10 aliens setups to counter that,. 25 levels is 25 setups for aliens, yeouch. For a 1 dollar game. No thanks.

So what to do ?
I am pondering what to do, and all development will be halted until i know what to do. Here are a couple of my ideas currently circulating in my brain.
Options:-
1. Reduce the number of upgrades to the first 15 levels. The the next 10 levels will have a constant firepower setup and i can concentrate on making them, play around with your skills, knowing the firepower you carry.
2. Give out firepower upgrades every so many levels, say just 4 major upgrades adn they happen every 5th level or so.
3. Make it so the Firepower is Earned.. I have 24 upgrades as is. So i could make it so killing a special powerup wave of aliens would 'Drop' the powerup. This means that if you miss the odd one, the game is harder  later. Not nescessarily a bad thing, but something i would have to take into account when designing levels. If you miss too many powerups the game could be impossible. Though that is sort of ok, as you need to get better at the earlier levels.

So i am not sure what to do.. I have no clear leanings atm either, so it's a tough one.
Laters