I don't think one pack is enough. I used the Astora boots on my 1984 300SD with there grease. After about 3000 miles I had a strange noise coming from the rear end. So, just to be safe I pumped about 4 oz of rear end oil in each boot. No more noise. Just to be safe I would use 2 packs of grease in each boot.
Harbor Freight has some nice stainless steel zip ties I have used with great success. See my other post on this subject. Just my humble opinion.