Hi
I too used to be frustrated by the limitations of PT le. I made the move and never looked back. Well, except for the Pultec EQs...
If I understand correctly, you´re willing to make another investment to get it right. So, all I can say is that I´m absolutely thrilled with the Mackie Onyx Series and the Firewire Option.
1. No Driver installation - standard Core Audio
2. Really good sounding Mic Preamps - a bit of warmth but without coloration of the sound. Very crisp highs without sounding thin, very dynamic and you get your 96/24 on 8-16 Mic Channels depending on which console you buy.
3. Not a single lost track, not a single lost take as of yet
4. Real mixing console with all the monitoring options (EQ is always post A/D conversion, so you can mix your headphone signal without compromising your tracks...)
5. No knitting a quilt out of all your patches

6. unlike with your patchworking, every Mic runs through the same Preamp and converter, which can not be a bad thing...
There is one con for me, as it can not produce the low latency a RME can, but I don´t play Softsynths so that doesn´t really bother me. A stable 128 - 256 Samples depending on the project can be achieved on your average iMac, I don´t know about the Mac Pro.
As far as giving the tracks to your mixing guy: just do a multibounce to export all the tracks (or the edited takes) as complete audio files of the same length and your Pro Tools-Wizard should be able to import it within seconds (if not, change da man). So it won´t really be much time loss compared to just opening the Pro Tools le session.