Need Help!

Hoping one of you out there in the great ether might be able to help me solve the following dilemma:

I'm using a Sanus SFV49 A/V stand as an audio rack.  Here's what it looks like:

I've got my amp and turntable side by side on the top shelf of this thing and need to provide more isolation or distance between my turntable and speakers that are on either side of this stand. I need to center both the turntable and the amplifier on the top shelf with the turntable above the amplifier on some sort of shelf or riser. Sanus doesn't make any accessory like this that would do the job. Wall-mounting the turntable is not an option. The amp is too big for a lower shelf and there's no room to put it on the floor on an amp stand. I'm wondering if an amp stand or an add-on shelf from Pangea, Vulcan, Salamander or a company like that might work. The amp (McIntosh MA5200) is approximately 17.5" wide X 6" high X 22" deep and weighs around 40 lbs. I'd like to have, at least, 1" of ventilation for it (i.e. 1" space between top of amp and bottom side of shelf the turntable would sit on). The turntable (Mofi Ultradeck+M) is approximately 19.69" wide X 6" high X 14.25" deep and weighs around 23 lbs. I'd be open to something custom-made, as long as it didn't cost an arm & a leg or my first born.

Any ideas, guidance, pearls of wisdom on this (other than "just buy a new rack") would be greatly appreciated! 
Don’t overlook man-made composite counter top materials. Quartz and Corian are very dense and have good resonance characteristics. Corian is my favourite because it can easily be cut and machined with woodworking tools. You can even make a layered Corian top with the middle cut out and filled with construction sand for a very nice look and even better resonance characteristics. 
I want to thank everyone for your very thoughtful suggestions.  However, I should have pointed out the problem I am experiencing is not from vibration(s), per se, but, rather, from acoustic feedback picked up by the TT cartridge at high spls.  At least, this is what an audiophile tech told me after I explained the issue in detail  The TT cartridge is so sensitive that I get a hum in the speakers at anything over a 50% gain, or so, on the MAC.  Loud, I know, but sometimes I just like to play things loud.  If this is, in fact, the issue then the only solution is to get the TT as far away from my speakers, as possible.  So, imhififan, I'm inclined to think your suggestion of the Pangea amp stand just may be the solution.  I hope so.  Otherwise, I'll have to consider much more drastic steps (i.e. high-end TT interconnects or re-arranging the entire living/listening room).  Thanks, again, all!
You might benefit from properly shielded interconnects from the turntable to your phono stage. The old way of using the signal return path (signal “ground”) is completely ineffective at blocking EMI and RFI noise. 
You should have at least 7 " of space in between shelves. You can place the amp on either the middle or bottom shelf. Place footers(I suggest cost effective Isoblocks) under the amp 1" in from the edge/ back of the shelf and let the 4.5" (20%) of the amp canterliver over the edge. There is enough weight - (the transformers are in the front of the unit, heaviest part) in the 17.5" (80%) of the unit that is directly supported by the shelf to keep it stable. I reccomend the bottom shelf to get the most separation.

Additionally I would bring your speakers forward toward your listening postion to get even more separation and better overall sonic presentaion. I also agree with those who suggest taking abother look at your cabling and investing in an upgrade if neccessary.

In general I don’t think glass is a good option for shelveing, here is another option to check out if you are looking to invest in a isolation solution.

Best Of Luck