King size. I've done 3 of them - 2 on a machine with a 7" harp and 1 on a machine with an 11" harp. Granted, the larger harp made it easier, but anything smaller than king size is a piece of cake. I'm not familiar with either of your machines, but a lap size quilt on either of them should be a piece of cake. I know I can do a lap size on my Brother machine which only has a 5 1/4" harp. Personally I find fmq a lot easier than sid on a small machine.

I've done as large as queen size. The key is to use a thin, low loft batting. Once I finally figured that out, machine quilting a large quilt got easier.

Have you considered a quilt as you go method? If I read your post correctly you haven't made the quilts yet, QAYG is one method to quilt. The nice thing about QAYG, when you are done constructing the quilt you are done quilting it at the same time. I used the Fun and Done method from Bayside quilting on the quilt that I made. It turned out lovely. Bayside quilting has several patterns available if you need a pattern. I made my own pattern, but, if you need a pattern, they have several for sale.

You should be able to do SID on that size on your machine. I have done straight line and SID on double size quilts on mine.. It can be tiring wrangling the quilt around especially when you are working on the middle sections, so take frequent breaks!

it's definitely possible... just a lot of pulling and pushing through that throat. i try to quilt with the majority of the quilt hanging out the front whenever possible

The two quilts I'm needing to do are:

[ATTACH=CONFIG]476209[/ATTACH]

[ATTACH=CONFIG]476210[/ATTACH]

Both of which I think I can do just simple, straight stitching on. I don't have a FMQ foot for either of my machines, so that's really my only choice at the moment :( HUBBY actually suggested we go down to the one sewing machine shop we have nearby and check out their used machines. HE actually suggested we start looking at a bigger machine for me :) I'm not quite sure if that's the route we need to go down right this minute, but I was impressed that he even suggested it. Lol

I have quilted dozens of queen size quilts on my Bernina. You just need support on your left side and you need support behind your sewing machine. Then you don't have any problem with the weight of a quilt. I look at these ads for sit down Long arm sewing machines and it just doesn't make any sense. A larger harp is convenient but not necessary.

If you want the look in the first quilt, then a LAQ with a frame is maybe what you need. I would have just crosshatched the Lattice quilt. The other quilt is just stitch in the ditch and slightly parallel to the ditch. Good Luck with making a decision.

I have made and quilted over 20 queen size quilts on my Domestic Size Bernina. My latest, a 100x110, I FMQ a rose and leaf pattern all over.
The trick is to have a large level surface. A way to keep your quilt on that surface (I used clamps around my desk) and you "nest" the quilt and work on an area in the nest.[ATTACH=CONFIG]476211[/ATTACH][ATTACH=CONFIG]476212[/ATTACH][ATTACH=CONFIG]476213[/ATTACH]

I've made several quilts around 80 inches on my Brother that has a 5.5 inch harp. Some SID, some straight line quilting. It's definitely not easy but can be done. I've tried quilting in sections and splitting the batting, I like splitting the batting so much more. Good luck!

I hate to keep bringing up the subject but you could hand quilt them. If the tops are already made you have more than six months to get the quilting done. You might be amazed how easy it really is. You could watch TV or spend time with friends and family while you are working. The second one would be extremely easy. You would just have to quilt 1/4 inch on either side of the pieced seams. Just use the seam allowance for your guide. Just think how amazed and grateful your aunts would be. If you don't have a quilting frame you could just use a large embroidery hoop. They sell plastic snap together quilting frames in JoAnns. Look in the quilt supply section.