For the cost and convience the sliver star sealed beams are OK, I put a set in one of our TJ's just before we headed to cape cod and I could pick my son's TJ out of the afternoon traffic on 95 just by the brighness. I have Hella E codes in my 98XJ, currently running 55/65W H4 plain jane's for bulbs, been too lazy to order another set of xenon bulbs. The main difference between the Silver stars and the Hellas as well as othe others like CIBIE and IPF, are the lense pattern. The silver stars are still the same old crudd design that sealed beams have been using forever, just brighter though they did put some light blocking so the low beams don't blind oncoming drivers. I may head down to AA and pick up a set of silver star H4 bulbs and give them a try in my hellas though thats a $40+tax gamble when I know the xenon bulbs from susquehanna will work well at $15 ea.
Tie the whole thing in with a good set of AIMED fogs and your night driving will be tranformed. The aiming of the fogs is very important though, too high and they don't light the road up in front of you, **** off oncoming driver, too low and you end up with a dead spot between the top of the fogs and the bottoms of the hella E codes. I have the hella 450's now but did have the 550's, the 450's put out the same pattern as the 550s only in a smaller package.
As for difficulty of converting, the converting is the same cept you have to put the H4's bulbs in the housings before you plug them in otherwise as long as you stay below 100w output the factory harness, if it's in good condtion, will work fine, just clean the headlight sockets with a burnishing tool or very fine small matchbook striker sized file and use dielectric grease so they don't corrode.