Laaz,
If my season is delayed a couple months in comparison to yours, do you think the Eustis limequat would have a good chance to still have good fruit into July or possibly August in Massachusetts? Do they hold well on the tree?

MrTexas,
When do you think an Indio Mandarinquat would be suitable for use up here in Massachusetts if planted in ground (assuming my season is delayed around 2 months from what you have)? The Meyer Lemon is going to be my backup plan... I'll switch to it if nothing else works. I can get Meyer Lemons in the grocery stores around here, so I'd rather give some more unusual stuff a shot first!

Also, I think I asked this before, but does anyone have any experience with Citrus glauca (Desert lime) and/or the Razzlequat (Eremolemon)?

Thanks for your suggestions everybody!

Scott, the Eustis is everbearing so if you can keep it from freezing you'll have fruit all year. You can use them green, and if left on thhe tree long enough will turn yellow. They hold on the tree very well.

I had a Razzlequat & didn't care for it, so it was top worked.

Oh, I would not put a lemon in a beer...

Nippon Orangequat

Thanks Dave,
Nice, helpful video
... I wonder how sour they would be for me in June/July?

They probably would not have much juice in June / July.

In Winter, they knock your socks off, like a slap in the face. Great in cola, tea, and perhaps even Laaz's beer! They hold well on the tree, but past Spring? Don't know. I've always finished mine before then.

Dr. Arlie Powell shown in Dave's video has been a loooong time friend of Bonnie Childers, ever since Powell's days at Texas AM (1968). In fact Dr. Powell is the man that got Bonnie into the citrus .- Millet

Dr. Powell seems like a great gentleman who has probably forgotten more than I shall ever know about horticulture. He has 18 videos which I found at https://www.youtube.com/user/petalsfromthepast/videos.

Dr. Powell was also the keynote speaker at the last citrus expo.....he is a great guy......Tom

Ok,
So far it looks like I am definitely going to try the Eustis Limequat. I'd like to start by grafting 3 varieties on to my FD rootstock, so I need to pick two more.

Any ideas for other choices?

It seems that the Orangequat would probably be past prime by summer for me, so that's out.
The Razzlequat doesn't appear to perform that well, so that's out (although if I can't find any other interesting choices, I may go ahead and try it)
I haven't come across any true lemons that would have a late enough season to be worth trying, so that's out.

Sudachi still seems interesting, although it would be for late summer/fall harvest.
What about the Sunquat? How similar to the Eustis is it?
Or possibly the Australian Round Lime, at UC Riverside they flower in Feb. and are ripe from July to Oct.
Not very cold hardy, but the Ponderosa Lemon is supposed to have fruit ripen throughout the year. This would give me at least one variety w/ larger fruit.
Meyer Lemon is still a possibility, although Frank_zone5.5 has one in ground in Massachusetts and I do not believe his has any ripe fruit during the summer months.

Maybe a Faustrime... Not sure how cold hardy they are, but they bloom throughout the year.

Mmmm... sounds like the Faustrime might be a good choice. It's a cross between the Finger Lime and Eustis limequat, correct? How is the taste compared to the Eustis?

Also, found this on Citrange's site:
http://www.homecitrusgrowers.co.uk/photos/faustrimefruit.html
From the pictures it looks like there would be a good chance of having some at a useful stage during the summer for me.

It's got a nice bite to it. I have a couple I grafted last fall.