Well this is what I did if it helps,
You could always go with these quick connect pt100's the cabling is better otherwise they are the same and they are 1/2 the price shipped... I bought 2 of these and use them, they work very well.
http://www.ebay.com/itm/380938165742?_trksid=p2059210.m2749.l2649&ssPageName=STRK:MEBIDX:IT
I also used this as an emergency stop.
http://www.ebay.com/itm/111435445439?_trksid=p2059210.m2749.l2649&ssPageName=STRK:MEBIDX:IT
and this element is a great alternative for the HLT I swapped my camco 4500w ulwd one for this because the base is lead free brass and wont corrode or rust... this way you can leave water in the HLT overnight to dechlorinate or whatever and not deal with rust. if you are sure you are only going to have one pot/element than go with the ULWD camco though.. since this is just lwd
http://www.ebay.com/itm/200909059093?_trksid=p2059210.m2749.l2649&ssPageName=STRK:MEBIDX:IT
I used this pot since with electric a thick walled pot is of little benefit ...
http://www.ebay.com/itm/52-QT-Quart.../360904639725?pt=Cookware&hash=item540797c4ed
I use bargainfittings.com for all my hoses, orings stainless fittings and sight glasses. His prices are really reasonable and so is his shipping.
Also I purchased dryer cords and ended up not using them.. they would be OK for the main control panel cord . you will wish you used SO-600v wire for the elements with quick disconnect plugs at the element base for easy removal and cleaning...I added this as well as the quick disconnects for my pt100 sensors on my setup after ruining a sensor by yanking on the cable by accident..
you will want to get sme wire for inside the panel... you need some 10 awg as well as some smaller stuff (18-20awg is fine) I even used 22-24awg for my circuts carring less than 1/2amp...)
and an alarm is nice too! if you expand and add a timer later you can use the same alarm for everything.
http://www.ebay.com/itm/1PCS-AC220V...416?pt=LH_DefaultDomain_0&hash=item19eabf1000
(here is link to a nice timer with 4 steps allowed for various hop additions)
http://www.amazon.com/dp/B008KVV546/?tag=skimlinks_replacement-20
Remember to buy a large enclosure so you dont run out of room for upgrades!
I used this one from the home depot.
http://www.homedepot.com/p/Carlon-1...-Box-E989R-UPC/100404149?N=5yc1vZbohnZ1z116nv
dont forget a couple of these for the end of your pt100 sensor if you want to get fancy and be able to disconnect them from the control box.
http://www.ebay.com/itm/XLR-3-Pins-...=US_Audio_Cables_Adapters&hash=item4181b26318