I had a laugh... ;D
This is a tough question mate, not knowing what your relos are likely to prefer. The "Sencha Green Tea" makes for a milder brew that has a nice fresh and sweet cup and is very more-ish. I havent tried the one that Andys got up for grabs though, got some as a gift a couple of years back but from the same region so it might be comparable..... ::)
On the other hand, the "Siaou Chu Pearl Tea" has more presence on the palate, especially towards the rear of the palate (for me) and the slight smokiness resonates in the finish and therefore makes for an overall more interesting cup. Youve got to be really careful with this tea though... Really easy to overdose the teapot if youre not careful as each little ball (pearl) of tea is a whole tea-leaf and if youre used to dosing the teapot with a teaspoon full for each person and one for the pot, youll end up with a brew that is way too strong :o. Probably only need to use about half the quantity you would normally use for other teas.
Why dont you buy 500g of each? You could then make a gift of small packets of each of them for your relos to take home with them. Its all extremely high quality tea you know and Im sure will be well received by those who enjoy a tea or two. All the best mate :)