they discontinued the nearest to perfect sprayer there ever was
http://www.rotovaccorp.com/sprayers-hydroforce.html
a 1.6 gpm Flowjet pump, 3 gal capacity and super wide opening to mix chems.
With an 08 flow tip, it will pump right at 1 gpm (about the same as an in-line)
You can't find them anymore
what's left on the market now are sprayers the size of small portys (which are too damn big and bulky for res work)
The Omni sprayer (do they still make that foolishly large for a little container sprayer?)
The Multi-Sprayer, which is an excellent sprayer, just wish it had more than 2 gal capacity.
The sprayers that utilize a Flowjet or Surflow pump with a minimum rating of 1.6gpm open flow is what you need for "in-line" like flow rates.
Note, the GPM flow is more important than the PSI
..L.T.A.