^^ +1 for RING XenonUltima 120% on a par with Osram Nightbreakers or Philips Extreme Vision, had all three now, no discernable difference in my opinion, but better than the standard OEMs.
I've put Philips Blue Vision w5w in the sidelights & now happy with an even 'white' light across all bulbs, far better than the manky yellow OEM sides.

HIDs are ok if fitted correctly, the muppets that have them fitted incorrectly need shooting, but really can't see the point in them. Personally not a fan, plus too many issues over the MoT 'legal' stuff, rather not have that agro'
 
If I were you I would just upgrade the Bulbs, I have Halford’s Ultra Brilliance Blue in my MR2 and I have been very impressed with them, nice clear white light, had them 2 years with no failures. Nightbreakers are also excellent.

I have OE HIDs in my FR which are excellent and also improve the look of the car and I’m pleased I specced them.

What I hate about aftermarket HIDs is that the vast majority not only look rubbish but they are actually dangerous to other road users. I often drive along the A27 in the morning and see a good few drivers coming the other way with aftermarket HIDs (a couple of vans and a Lexus IS200 on Friday) the glare is horrendous, cant see a flipping thing, how they pass an MOT god knows – please don’t fit them!