A friend of mine wants to start up 40k, he likes the rules and everything, but he doesn't like the fluff of any of the armies he has looked at so far. What he wants to do is create an army based around the RIFTS roleplaying game universe. The army will be heavily converted, but needs a base army list from which to draw units. He wants to include some of the iconic classes associated with the rifts universe as units in his army. Some are easier than others, and any input for options would be appreciated.

Juicers- Super soldiers that augments his or her body though the use of chemical enhancements. They are faster, stronger, and tougher than normal humans, but their lives are drastically cut short by the process, making them easier targets. Juicers' physical attributes are at least twice as good as an average person's and some can dead lift over a ton, run over 50 miles an hour, and manifest psychic ability.
Coalition- Trained soldiers who form the majority of the army. They have helmets with a skull symbol on them.
SAMAS- A powered armor suit (larger than the "power armor" of 40k) that has heavy weapons like railguns, missile launcers and machine guns.
Mech- large walker type vehicle, standard "mech."
Mercenaries- poorly trained troops who use whatever weaponry they have available to them.

If there are other classes that you guys know of like ley line walkers feel free to add their 40k equivalent too. So far I am leaning toward suggesting a Deamonhunters army with inducted IG, or the other way around.

So far the ideas thrown around are:
Juicer: Space Marine, Arco Flagellant, Grey Knight, Terminator
Coalition: Guardsmen, Storm trooper
SAMAS: Crisis Suit
Mech: Dreadnaught
Mercenaries: Guardsmen, Conscripts

Ok, having been a big fan of the "Rifts" RPG back in the day, I was intrigued by your endevour. My idea would be to build a Daemonhunter/Witchhunter army with some inducted Marines.

Your Inquisitor Lord and Retinue with their Psyker powers fills your Ley Line Walker/Mind Melter slots, hell you could even make some of the retinue Cyber Knights, or use some of the Necron models as Cyborg Gun Servitors

Any space marine can fill in for the Coalition troops, convert some with wings and your assault marines are now SAMAS units

Imperial Storm Troopers fill your mercenary role.

I think any of the Assassins would make good Juicers.

That's all I can think of off the top of my head. Like I said, with the variety of troops and powers available to a DH/WH army with inducted troops would easily fill you Rifts need.

Thanks for your help, I had hoped that more people would have gotten involved.

In this age of instant communication it is a little too easy to get carried away into thinking that we will get an instantaneous reply. This is often not the case. LO is an excellent forum in part because it has a large number of members with a broad range of experience and interest in the hobby and everything that goes with it. That means that if you ask a mainstream question you will probably get an answer almost straight away from someone or another.

If you ask about something a little bit more obscure, like Rifts for instance then you may have to wait a teeny bit before the people who can best contribute are available to help.

The Rifts universe is awesome, with a great background that shouldn't be too tought to port into 40K. I think you will find that with a little more patience you will find some excellent suggestions coming your way.

Oh and by the way, it's a great idea!