Return Pump ideas and suggestions

[HOB]

Got home last night and my return pump (hammerhead) was making a lot of noise – more like a grinding than a rattling sound .  I took the cover off and cleaned it.  There was some salt build up on the outside, inside the shroud - maybe a leak.  I put it all back together and the noise was gone.  Woke up this morning and the noise was there again. So first question is - is this pump toast as it still pumps water like is used to?  Are there bearing or seals that you can replace?  The pump is not even 3 years and 2 months old - I say this because it has a 3 year warranty!

If I have to replace this pump, I was thinking of going with two pumps – one external and one internal.  I would run the internal one in the winter (now) to help heat my water (as of right now my temperature goes from 76 in the morning to 80 in the evening when the MH are on).  I currently use 2 x 250W heaters.  Then in the summer, I could get an external pump and run that so not to add any extra heat to the water.  In the summer, temperature runs 78 to 84.  Plus I would have two pumps if one should fail.  Is there enough heat added to the water to make this worthwhile?

Some background info:
My sump is in the basement and the return line (1.5" spaflex) has to go up 9 ft vertical, then 21 feet horizontal in between the flooring then up 7 feet vertical to the display tank.  Volume of water is 350-400 gal.  My drain pipe is 1.5" that flows from the aquarium into an external overflow box right beside it set up Herbie style (2 x 1" overflows) with 2 external wave boxes on each corner.  Have 4 Tunzes (2x6100's and 2X6200's) for flow - mainly LPS and softy tank.

Next question is, what internal and external pump would you recommend if you factored in price, reliability, GPH for the distance to travel and efficiency.  Currently, I had to throttle back the hammerhead just a bit for the overflow to handle it.  I'm also considering only one pump that can be used both internally and externally and switch according to the time of year - they seem to cost a bit more.

For external, currently considering another hammerhead or moving down to a barracuda.  I have an extra Dart laying around but I don't think it will handle the head pressure - I'll probably try it this weekend.
For internal, I'm not sure.......a Mag 36 but not very efficient.
For an all in one internal/external pump, something like a Marinetech Pump (4500Gph) @ 120 Watts but $700.

Just looking for comments, suggestions.........

[nissannx]

does teh quiet one make a pump with enough gph? you can run it both internally and externally if it is strong enouh