Best Custom IEM for simple iPhone source?

[listenCarefully]

I've been toying with the idea of going all out on a custom  IEM but want something that is optimized for a portable source such as an iPhone. I am a little worried that I might invest  $500-$1000 on something that people rave about only to find out that it needs an  outboard amp to really sing. Most people who get a no holds barred custom are willing to get whatever portable amp that is necessary to optimize their performance so I can't really find much information on customs specifically designed for portable sources. Any thoughts or suggestions would be greatly appreciated?

 

[squallkiercosa]

Check this guide out. CIEMs are usually easily driven (with some exceptions) by cellphones 
 
http://www.head-fi.org/t/541494/multi-custom-iem-review-resource-mfg-list-discussion-24-reviews-ultimate-ears-personal-reference-monitor-added-12-08-12

 

[Spyro]

Buy the JH5.  At $400 its the best money I have spent in 10 years here on Head-Fi no question. It has dual sound bores so it easily competes and out performs universal triple and quad drivers.  I am a big fan of JH5.  Go ahead and do a search.  I'd be shocked if you found one negative comment on them.  If my pair broke or got stolen I wouldn't think twice about getting another pair.  They are amazing! (and I owned JH13 and JH16).