I think that most worth owning would break your bank.
Moreover, the guard isn't needed, and may hang up on brush.
I have seen many Bowies made by members of the American Bladesmith Society, and none had a D-guard. You could probably order one and get someone who'd build it, but it'd cost more than their work already does.
You might look at the Fallkniven NL-2 if you want a functional Bowie with eight-inch blade at a fair price. You can get a longer blade in their NL-1, but that blade is pretty thick, although the knives are very well balanced. Read their site:
www.fallkniven.com I think they offer the best Bowie styles that you can buy without a waiting period. They are sharp and they are tough. They're also very good looking!
The ciip isn't sharpened, but you can have that done, if legal where you live.
Otherwise, I suggest a Randall Model 1 with seven or eight inch blade. They have bigger true Bowies, but they're so big and heavy that I think you'd prefer a lighter knife with the same basic characteristics. Randalls aren't made as consistently well as Fallknivens, and there's a long wait. And Fallkniven uses a VG-10 blade core that'll hold an edge exceptionally well. Their NL line does cosmetically resemble Randalls, BTW, although blade finishes are usually better.
Fallkniven knives are expensive, but less than you'd pay for most custom work that's no better made. And they are available for immediate delivery, if you find a US dealer, and there are some. (The company is Swedish, but they are NOT cheap Mora knives!)
Be sure that it's legal to carry a Bowie where you live. I know that you're in LE, so you should have that info.
If I encounter any decent D-guard Bowies, I'll give you a shout. My own taste in Bowies of the classic sort is the Sheffield style.
Oh: If, like me, you don't like the dip in the blade spine just before the guard on the Randall Model 1, order the Model 5 and have them sharpen the clip, if wanted. Except for the blade dip and the sharp clip, the knives are otherwise the same. I ordered a Model 5 that way, and was very pleased.