iPhone amps that have minimal interference?

Well, I recently bought an iPhone and a nice LOD from another Head-fier here, and was looking forward to using it with my ibasso T4... when I was hit with the nasty reality; the T4 does HORRIBLE with cellphone interference, creating nasty static once in a while that I simply cannot tolerate. So while I have really loved the T4 over the last few months, it simply won't be feasible to use it anymore since iPhone 3G is now my main portable source (and I'm not gonna put it in airplane mode since that loses the phone part, and not gonna wrap it in aluminum foil or anything either).

So here is what I am looking for:

1) First and foremost, a portable amp that will do very well against cellphone interference. I recognize it won't be perfect and it doesn't need to be (minimal interference I may be able to put up with), but I don't want abundance killer buzzing noise whenever there is a cellphone transmission.

2) Smallest form factor. T4's small as it is so it'd be hard to find another amp that small, but smaller would be much more preferable. Stuff like Hornet or Tomahawk would be too big for my needs. Maybe the new Pico slim or the rumoured T3?

3) Cheaper the better. I've realized that personally for me, portable amps are not something to spend crazy amount of money on. I'd go up to $200 if necessary, but any more than that may be overkill for my needs. Rules out amps like D10 or Pico.

4) Must do well with low impedence/high sensitivity stuff. Particularly because my main IEM is SE530 and T4 didn't do too well with it (ugh, the hiss).

5) Good SQ, obviously. I won't be interested in any amps that is inferior in SQ than T4. Yes, that rules out E5.

Thanks in advance!

I've heard of the Penguin amps and have heard good things about it, but haven't really considered it. They might be bit too chunky for my needs I feel (they're size of Altoid cans like the Cmoys, IIRC? I do suppose they'd do very well against phone interference due to their aluminum box). I guess the size of the T4 got me really spoiled.

I think it'll probably come down to Pico Slim and T3 but I'm waiting on the word on the price for both of them. I have a feeling the Pico slims going to be on the expensive side, too, and I'll need verification on how it does with phone interference first.

Knowing RSA it probably wouldn't be in my price range. but perhaps I'll need to raise the ceiling on the price a little in order to get a decent one.

Any other experiences? Someone here's gotta be using some sort of amp with their iPhones!

Good point about the LOD part. Haven't thought about it. I bought it from another member here and the LOD is built very well, but I'm not really sure about how it would perform against the RFI. Something I'll need to consider.

My IEM's connected directly to the iPhone do not have any buzzing problems whatsoever. My SE530's are actually connected to the Shure MPA adaptor, so it obviously doesn't have any problems. Once in a while I use my PFE's with it as well, and they don't have any kind of buzzing either. So it's probably not my IEM's.

I guess my best bet would be to try to find the amp with the best filtering and see if it is indeed more of the LOD's fault. Or else I'll just have to go ampless and sell off the LOD. I guess on the bright side, the 3G headphone out is at least decent on its own (compared to my old 1G touch anyway... that had some terrible hiss).

Thanks everyone for the input.