ricred1, My friend owns the Audio Research L28 line stage preamp and likes it very much. Please see:
http://www.audioresearch.com/en-us/products/preamplifiers/ls28
I have no experience with Jeff Rowland or Audio Research. If possible, I suggest you demo the ARC L28 preamp in your system and see how it sounds compared to the Rowland. Based on what I have read, I probably would stay with the Jeff Rowland equipment but you need to make this decision based on what you hear.
http://www.audioresearch.com/en-us/products/preamplifiers/ls28
I have no experience with Jeff Rowland or Audio Research. If possible, I suggest you demo the ARC L28 preamp in your system and see how it sounds compared to the Rowland. Based on what I have read, I probably would stay with the Jeff Rowland equipment but you need to make this decision based on what you hear.