Wyeast cracked, wort not below 70°..

Probably because you are using ground water and it won't get much colder than that.
Has the smack pack expanded like a balloon yet?

Consider getting a pond pump and circulating ice water through your immersion chiller to get the temp where you want it.

 

If it were me, I'd pitch the yeast and put it in your fermentation chamber to chill. 77 isn't terrible, but it isn't ideal either. I've (many have) pitched at hose temps and made decent beer. To be honest though, I'm not sure how long the smack pack is good for at room temp, and now being proofed.

 

I'd wait until the wort is down to whatever temperature the original plan called for.

 

Can anyone recommend a pond pump and parts necessary to connect it to my immersion chiller?

 

Hmmmm, how about this?

https://www.amazon.com/Superior-Pump-91250-Thermoplastic-Submersible/dp/B000X05G1A/

Also, what do you put the pump in? 5 gallon bucket of ice water?

 

Here's the one I use...
https://www.amazon.com/gp/product/B0000AX09E/ref=oh_details_o00_s00_i00
It came with an adapter with threads for a garden hose end. Since my chiller was already set up with garden hose connectors, I didn't need to add any special parts to connect to the pump, i.e. I just kept using the same two garden hoses.

 

I just use a large pond pump from homedepot. If you are doing 5 gallon batches, you probably want something bigger than a 5 gallon bucket of ice water. I use a largish cooler, probably about 40 quarts and blocks of ice that I make in my chest freezer.

 

Ah, got it, sounds good.

 

Eco smart 396, and 594 gph models come recommended. I use the 594, I've talked to others that have had good success with the 396. They come with barb adapters to go onto hose. I use ground water to lower the temp to 90, then switch to a cooler with ice (15 lbs). I have not tried freezing ice blocks myself, but hear it works well if you freeze enough.

 

So you cannot screw your garden hose onto the pump? How do the barbs work?

 

I use the Eco 396 and recirculate using a cooler. I use freezer packs that I throw in the freezer the day before brewing for the bulk of the heat loss, then usually use the bulk of the ice from my ice maker at the end to get the last 20 degrees or so. I have 15 or so large reusable ice packs I use and could probably use more. Bit of an investment up front, but I waste very little water in the end so in the long run I feel better than running my hose for 30 minutes wasted.

Couple tips, move the IC around while cooling and put the return hose on the other side of the cooler. If you put the return next to the pump, you'll just recirculate hot water.

 

Thanks, good tips!

 

http://lmgtfy.com/?q=Barb+adapter+fittings

Barb adapters allow you to skip a hose over them and clamp the hose down.