ToolBoxTavern,
  
I love my R1s.  I know they have gotten me out of slimy clay before and I really think R4s would have left me lifting the tractor out with the backhoe and loader.  My trailer fenders are still attached.  It is the inner skin that is tack welded to the inside lip of the fenders and the trailer frame that is loose on the back end, where the tractor's rears ride.  
I want to keep this trailer for farm (has farm tags) use and get a 25 foot dual tandem for commercial work.  That way I won't have to put the loader bucket up on the gooseneck.   The photo below shows this.  My 2002 Ram 2500 with Cummins pulled it okay, but now I have a 2003 one ton dually that makes me legal in the weight area.  The 2002 was only rated to pull 9800 pounds.  The tractor and trailer weighs 11,700 pounds.    
Happy trailer hunting!
Oh yeah.......R4s on front and R1s on back will screw with your traction/slippage .vs gear geometry in 4WD and bind your drivetrain.  Which is bad jeu-jeu and tends to void your warranty.
             hugs,  Brandi
		
		
	 
This whole R1 or R4 thing is a bit aggravating, but I know I am going R1s. Just makes since and I believe it will suit me better since I'm wanting to set up for a bit of AG work. Large garden type deal. Just trying to set up for when I retire, but that is still 25+ years away, but we are trying to get our toys and retirement gig ready while we can and looking at a produce stand out front to supplement retirement income. Guess I maybe thinking way to far ahead. Still just cant get over the R4 look on the unit, but that aint being smart goin for looks versus functionality so I know what has to be done.
I get the gear ratio and different tire thing, but when looking at the tire sizes on the spec sheet or mahindra web site I think it would work because the R4 front it only 1/2" taller than the R1 front and the R4 rear is actually 4" shorter than the R1.  So having the R4 a 1/2" taller seems like it would work better with the R1 since it is 4" taller and less of a difference between the rear and front.
I got a 2000 F250 auto 4door (family of 5 here) with a V10. Prefer diesel since I own and operate big truck and tractor will be diesel, but couldnt pass up deal on pick up. I believe my tow capacity is 13,000lbs, but I will have to look again. I actually plan on this trailer being used for farm a lot. I'm even kicking idea of making a removable livestock cage or everything above the floor like a live stock trailer that can just be removed. I think it will be kewl to have like a all in one trailer. I like that your trailer, tractor, and truck is red, but here I go with the looks again...lol.
I think I might step down to a 5ft shredder thou and stay with the 6ft tiller. I really like the unit having 167 cubic inch and NO turbo. I think it will manage the 6ft shredder, but if I get in tall brush/grass I want to be sure it will not have a problem. Not worried bout tiller since I will do some plowing or middle bustin 1st to take stress off it.
Great talkin with you. 
O and I am on a run where I currently drive by the Mahindra assembly/distribution center in Houston everyday and hurts my feeling I dont have time to stop.