I'm a high 90's golfer and basically play golf one handed with a little support from my right hand due to birth defect.

I'm basically looking to buy a new set of irons and was considering to purchase graphite with a senior flex. My 5 iron is around 155 yards give or take.

I was considering something like Nike slingshot OSS or something along those lines. Does anyone have any thoughts if I'm in the right direction or not?

T, welcome!
you are looking in the right direction...it's the category called "game improvement" irons. Generally larger faced irons, perimeter weighted, gets the ball in the air easily.
Try to find a way to get some demo's outdoors if possible to compare ball flight with a couple of different brands. If not, hit them indoors and see what feels balanced to you.
If you get a chance to hop on to Golf Digest's site I think they have the "hot list" posted from a few issues back, it will give you a couple of ideas of irons to check out.
Remember that there is a significant cost savings buying last year's model vs. the newest...so for example, if you like Callaway X-20, look at X-18, which is essentially the same.

Thanks, I tried the X-18 today at golf store they felt really good (good price as well). I wasn't able to compare to the Big Bertha '08 though (extra $310).

T, Golf Magazine just put out there ClubTest which has Game Improvement and Super Game Improvement irons and reviews by testers. It's online to at http://www.golf.com/golf/special/article/0,28136,1726355,00.html

The more game improvement (super game improvement) you get, as I understand it, the easier it is to get the ball in the air and keep it straight but you lose the ability to 'work" the ball left and right on command. I know the Cobra S9's got really good ratings but check those out and see if something clicks.

Good luck and welcome to the site. Let us know what you decide to buy and how you like them. Plus don't forget to add a review on the club review section of this site. you might win a door prize even...

Best bet is to actually go out and demo the clubs yourself, preferably at a range.

This is the only way you'll know what feels good along with performance at your level.

After finding something that works for you, get your clubs fitted by a pro.

I completely agree with DocT. You need to demo clubs for yourself before you can actually judge what is good for you. The reviews of clubs are one thing, but can be extremely subjective. I have seen some irons reviewed in club tests that do extremely well and then in another review get completely opposite reviews.
Good luck in your search...

-Rob