Having Two Iteration Methods in a Loop

OS: Win10
PsychoPy version: 3.6.5

Hello guys,
I am new to Psychopy and would be thankful if you answer my two questions:
1- I have an Excel file with two parameters (i.e., consonants and inter-stimulus intervals) and I want to build a loop which iterates through the values of my consonants parameter in a fullRandom method while iterating through the inter-stimulus intervals parameter in a sequential method. How is it possible in the builder mode?

2- I wanted to know if it is possible to choose 9 out of 21 consonants of my Excel file randomly, as my text stimuli.

Thanks in advance.

With regard to question 2, have a look at this post from Michael: Randomly selecting a subset of 5 excel rows from groups of 10 rows on each trial

Hope this helps.

Jan