You can do some beautiful quilting on your smaller machine using the various Quilt As You Go techniques. I learned to fmq on my Juki2010Q. When I decided I wanted a better setup for big quilts I chose the Juki longarm in the table. I am just better with moving the fabric than moving the machine head, probably from the years of fmq practice on the smaller Juki.
Don't just get a longarm because other people are doing it... be sure that is how you like to quilt. Try lots of machine options and find out what you are most comfortable with. I found my best fit was the sit down longarm.
I bought my sit down Juki longarm at a show, where they gave me a great deal and threw in lots of extras. They offered 0% financing for 5 years, so I am paying only $94 a month for my machine. Quite doable. If you wait for sales events, other brands will offer 0% financing too. At the show I looked at the APQS machine too, but they didn't have free financing. It also cost about double what the Juki cost.
I took an fmq class at a local Babylock sales event recently, and they were offering 0% financing and great discounts too. They have fabulous machines. Take your time and look around. Find out what you like and wait for a sales event!