Excel formula Q

OK here goes:

In a data sheet (sheet 1) I have the following columns:

A: Qty
B: ItemType1
C: ItemType2
D: ItemType3

My end objective is to have a formula that will lookup the highest quantity based on a given criteria of Item Types. (It should also allow me to select the no2 position, no3 position etc...)

Through searching on line, I have managed to piece together the below array formula, which gives me most things, but I would like to add a coule more.

Formula is located on Sheet2 for example:

=IF(SUM(('Sheet1'!B2:B300=D3)*('Sheet1'!C2:C300>=E3))>=1,LARGE(IF('Sheet1'!B2:B300=D3,IF('Sheet1'!C2:C300>=D3,'Sheet1'!A2:A300)),1),"")


Additions on the above array formula:

1. To include a third criteria (as the above only allows two to be defined: in cells D3 and E3).

2. To include a flexible amount of rows to be included in the range. As the rows of data will change, I need something that can compensate for this. (I used a countif: =COUNTIF(B:B,"<>" to retrieve the number of rows with data, but I'm not sure how I can put this in the formula. If take the total column (A:A) than I get an error in the formula as the array has empty cells.

3 To have a seperate lookup formula, that I can use like a 'vlookup' on the row in which the qty is matched. Example: The 2nd highest qty matched is 500, so I would like it to look up across this and provide me with the ItemTypes that it was matched to.

Any help is much appreciated!

EDIT: In additional to #1 - is it possible to have my criteria match on a partial value? Example: ItemType1 data could contain, "Telescopic" "Televisions", "Telescope" and I would like to be able to match it using the equivalent of a "begins with" Tele.