Jeff, most of the DSM guys here are AWD, you may wish to pose your question
at www.dsmtuners.com and also at  www.dsmtalk.com
I have 235/45/17 on 17x8 +42mm wheels and in the rear there is precious
little clearance but this is with an AWD car.

There are several issues here.

Your current wheels are 5.50J4 with a 46mm offset. 195/70/14s are 62.9cm
rolling diameter.

Standard Eclipse 205/55/16s on a 6.0J16 are 63.15cm, 225/50/17s are 65.70cm,
235/50/17s are 66.7cm.

The 17x7+40 wheels inner edges are approx 8mm closer to the struts, which is
OK.

If your car is AWD, you MUST have the exact same tire (not just the same
size) or you risk frying the $1100 + in$tallation vi$cou$ coupler in the
transmi$$ion.

The 225/50 will probably just fit, but the 235/50 is likely to foul the rear
wheel arch, aside from having bigger rear ties being pointless. 235/50's on
the front may foul the spring cup.

You really need something in the range of 62.9 - 63.2. ie a 45 profile tire,
otherwise your speedo will be wrong (slow).

So I advise to forget these tires.

The final issue is the centerbore of the wheels. On the DSM this is 67.1mm,
while the Nissan (std) is 66mm. Most aftermarket rims have adapter rings the
snap into the centerbore. You HAVE to have the rim align itself on the hub:
just the lug nuts is not enough or you'll get vibration. If these 17x7 rims
are factory Nissan, they WON'T fit on your Eclipse unless you
a) have the centers bored out (expensive); or
b) have all four Eclipse hubs turned down to 66mm (less expensive). Hubs
have to be removed for this.

I advise you to probably forget the rims too. The owner may sell just the
rims if the center bore is OK.