I owned Jeff Rowland Capri preamp and was rather happy with it. However, when I got Joule-Electra LA-300 preamp I learned what "sonic paradise" is all about.... No comparison between two. These both preaamps are similar to that you asked.
"....price wise one cannot compare the LA 300 to the Jeff Rowland "
Its not exactly true statement. I paid for my Capri quite a bit and Joule-Electra have many promotions.
At worst, instead of LA-300 you can get LA-150 SE as Coxhous did and you will have 85% and half price of "300". Even entry level LA-150 Mk2 will bring you to increadible musical involving level of listening to music. These preamps do not need much attention, 24/7 are warmed-up, you need re-tubing once in 5-10 years, highly relaiable etc.