I hate hop spiders. When I had a Brew Monk I had one of these from Angel Home Brew. It worked brilliantly and kept the pump clear. If it fits your kettle it is a great accessory. It actually worked better than the bottom filter on my new expensive GF G40...
The GF is a great bit of kit (I have one and love it) but for very large batches such as you are contemplating, I think you would find it a pain standing feeding the hopper for ages. A larger (motorised) mill with a big hopper would suit you better.
I have my G40 on a home made deep trolley, which is high enough to enable me to get a standard size bucket under the drain tap. I use heavy duty casters from B&Q - two are lockable but I never use that feature - the G40 is heavy enough to be quite stable without. The overall height of the...
Before I got thermowells, I used to use a length of pipe insulation (the stuff like silver mylar with a bubble wrap core - about 40mm wide). A couple of bits of self adhesive velco fixed it neatly and it held the probe snugly against the fermenter.
Adding sodium metasilicate to sodium percarbonate makes a good PBW clone. In hard water areas it is advisable to add a chelating agent. If you search for "home made PBW" there is a lot of information available. Tri-sodium phosphate is a de-greasing cleaner and is not part of the PBW clone...
GF have just introduced Firmware 1.8 for the G40, which gives the option to vary power during the boil. I used it today and it really is a great feature: I boiled at 85% power, which gave a nice rolling boil without the excessive activity of a full power boil. A small saving in electricity and a...
I use gelatine finings but never cold crash. It works well for me (and has done for over 50 years).
I have recently been using CML California Common as an alternative to my usual Nottingham, and I have found it very good.