Optimal SSD based RAID 0 config

I would like to ask the community for their kind support.
I'm looking for the optimal configuration of postgresql
under the following assumptions:

# Database usage scenario:

```
* daily bulk upload of several million rows of financial transaction data
* Statistical analysis (possibly machine learning) using pl/R and pl/python
```

# My hardware spec:

```
* ASUS WS X299 PRO/SE LGA2066 ATX
* SAMSUNG 850 PRO SSD 256GB intern SED 6,4cm 2,5Zoll SATA 6Gb/s
* INTEL Core i9-7900X 3,30GHz LGA2066 13,75MB Cache Boxed CPU 10K
* 128GB DDR4-3000 CL15
* 2x HGST ULTRASTAR SN260 SSD HH-HL 3200GB PCIe MLC RI 15NM HUSMR7632BHP301
```

Operating system is Linux (preferably debian jessie or gentoo).
I would like to use the 2x ULTRASTAR SSD PCIe in raid 0 mode to maximize
the I/O throughput.

In particular I'm looking for the the allignment of the following
parameters:

```
* postgresql block size
* Kernel PAGESIZE
* RAID stripe size
```

Best regards and many thanks in advance