An IMAX 2000 will outperform both the A99 and the MACO V5/8.
http://www.www.premiere-electronics.net/store/imax2000.html
If you get an IMAX 2K try tp put it up, (as Marconi advised in another post) at least 20' above the roof, then guy it well with 4 guy wires per 10' section of mast.
Here's what will help you get the best performance:
Add insulators to the top set of guy wires at 8' 8" down from the top of the antenna's aluminum mounting plate.
What I did is drill two holes about 1/2" apart and 1/2" from the top of the Aluminum mounting plate, and 1" from the fiberglass and put a pair of closed eyelet bolts facing 180* off from each other so two of the guy wires attached to one eyelet (ie: the N & W guys) and the other two (E & S guys) to the opposing eyelet.
8 feet, 8 inches down the top guy wires (peaked for ch.38 ) I placed a ceramic or 'Egg' (porcelain) interlacing insulator on each of the top 4 guy wires which effectively made them into 1/4 wave ground radials, or a 'counterpoise' and I saw about 1 S-unit improvement on both receive and transmit at ~30miles plus.
It's really not hard to do and only takes a few extra minutes.
The IMAX 2000 antenna system outperformed the MACO (which was on the same mast, coax & radio) by about 1 S-unit without the radials and about 1.5 to 2 S-units with the radials.
The IMAX is 24 feet tall, not 19.8' or so like the MACO.
The IMAX is a .64 wave antenna whilst the MACO is closer to a 1/2 wave.
You'll have noticeably better performance on both receive AND transmit on the IMAX than the MACO, and MUCH better performance than the A99.
You won't match it, but with 500w - 1Kw power handling you will come about as close as possible to the performance of the I-10K for any antenna available on today's market, and for about 1/3 the cost.
So, unless my experience was different, and I don't see why it would be as these antennas were all assembled correctly, tuned and used just like anyone would, this is the level of comparitive performance anyone should see.
- Hey Marconi, whay haven't you upgraded to an I-10K or an IMAX 2000?
73