Rick,
You are smart and brave. Just remember that either of these modifications takes you away from a stock appearance, which may be of greater or lesser importance to you.
There have been a few posts about the DaviesCraig water pump for the Elan. And several more for other cars. Do a Google search on Davies Craig.
The DaviesCraig website has words about the heater.
And several Elan people have converted to the Sirocco radiator.
You are smart to position the radiator as far forward as possible. Depending on how the components are placed in the nose of your car, it is possible to position the radiator completely to the front of the car and leaning forward. That way, the intake air goes immediately through the radiator, rather than tumbling in a turbulent manner through the nose to the current radiator position, where the air flow is not used very efficiently.
Then you have to deal with the airflow from the radiator. There are several posts from people with different solutions, ranging from holes in the front wheel wells (the maintenance manual deals with that), to ducts at the rear of the hood (a couple of illustrations of that), to letting the hood raise proud at the rear (an ad hoc solution often used by vintage racers), to vents on the side of the hood, to vents in front of the hood (like some mod sports cars).
Each of these has its advantages and disadvantages, especially when it comes to retaining a completely stock appearance.
One of the interesting side effects of the electric water pump is the fact that you will gain a little better acceleration since the water pump is not absorbing power at all times and the electric water pump only runs when necessary.
There is a post that allows you to model the effects of the electric water pump.
http://www.lotuselan.net/forums/viewtopic.php?t=15596
What ever you do, enjoy the results.
David
1968 36/7988