the price for kirbans assembled with his applique is the way to go...and i think hes a little cheap on the assembly
as far as i know the WOM is the same one kirban is offering assembled but altered to fit and look more correct
the problems with doing the assembly yourself with the kit from WOM is the gauges dont align to the bezel and the bezel itself needs cutting for depth ,a backer is not included in the WOM kit so you would need source one out or pull yours and modify just to begin the mock up (fwiw its all detailed in the instructions but you have to ask yourself why its sold as a kit if it needs so much modifying to the parts just to work )
doing the WOM kit could easily cost you over 1K for the install if your paying someone and thats if they care about the way it installs ends up and dont just give up on it and unless they have experience with the WOM the end result wont be great , my bet is if they ever played with the WOM they wouldnt touch another one
the WOM can be made to work following the directions but as dennis mentioned his is assembled to a backer and gauges aligned ready to bolt the backer into your dash making it a gauge kit you could install youself and be pleased with the final product . just need to remove your original cluster and backer , remove the wiring case , drill duct behind speedo for the speedo cable, install new upper cable and oil /water senders on motor, connect tach lead and plug in the SES wire
i did the WOM kit with kirbans applique and understood the problems going into it (Dennis didnt have the assembled units at the time). I had to do multiple installs on the bench using a spare backer and then even after i thought i had it right it took multiple installs in the car to get it right ..before install in car i modified the gauge plate and the face plate , i was after a GNX correct appearance so i changed out the incorrect looking 30psi boost gauge (no color but resembles the original gnx 15psi gauge ) I also replaced the tach (it worked but the look wasn't correct for 87). after install in the car I had issues with the gauge functions . had to change out the speedo that WOM broke modifying for vss pickup luckily i found a correct original 87 gnx speedo and at that time also changed out the incorrect functioning fuel gauge (the WOM supplied gauge wasnt for the gm 90 ohm sender so had to get a gauge from summit ) ,